Interleukin-4, soluble CD23 and interferon-gamma levels in serum during the first 18 months of life.

Serum levels of interleukin (IL)-4, interferon (IFN)-gamma and soluble CD23 (sCD23) were analysed in a prospective study of 64 infants monitored from birth to 18 months of age. The levels were low at birth and then increased, reaching a peak at either 6 or 9 months and then decreased up to 18 months of age. The children who developed atopic disease during the first 18 months of life had significantly higher IL-4 median levels than those who did not. No relationship was seen between the levels of sCD23 and IFN-gamma and allergy. Thus, the IL-4 levels in serum, but not sCD23 and IFN-gamma, were associated with allergic disease in infancy. Elevated levels were recorded before the onset of clinical symptoms, indicating that atopic disease is associated with a primary deviation of T cell function.